Such methods for determining the rotation angle position of the camshaft are known from practice. A planetary gear train provided as the actuating gear is connected by its drive shaft to a camshaft gear wheel in a non-rotatable manner, the latter being mounted rotatably in relation to the camshaft and being in drive connection with a crankshaft gear wheel via a drive chain. An output shaft of the actuating gear is in drive connection with the camshaft and an actuating shaft is in drive connection with an actuating motor. When the drive shaft is stationary, the gear ratio prevailing between the actuating shaft and the output shaft is selected by the actuating gear and is known as the stationary gear ratio. When the actuating shaft rotates, the gear ratio between the drive shaft and the output shaft increases or decreases, depending on the direction of rotation of the actuating shaft in relation to the camshaft gear wheel, so that the phase angle of the camshaft changes in relation to the crankshaft. In comparison with a method in which the internal combustion engine is operated at a constant phase angle, better cylinder filling of the internal combustion engine is achievable by adjusting the phase angle, thereby saving fuel, reducing emissions and/or increasing the output power of the internal combustion engine. To regulate the phase angle at a setpoint signal, the rotation angle of the crankshaft and the actuating shaft are first measured with the help of inductive sensors and then an actual value signal for the phase angle of the camshaft in relation to the crankshaft is determined with the help of the known stationary gear ratio. At a reference point in time, an interrupt is triggered in a microprocessor-based electronic control unit; with this interrupt, the measured value for the rotation angle of the actuating shaft is input into a regulating unit and compared with a setpoint signal that is made available. When a deviation occurs between the measured value and the setpoint signal, the regulating unit triggers the EC motor in such a way that the deviation is reduced. The rotation angle of the actuating shaft is measured with the help of magnetic field sensors which digitally detect the position of magnetic segments situated on the circumference of the EC motor rotor. However, since the measured values are digitized and the reference point in time differs from the measurement points in time of the actuating shaft, there are measurement inaccuracies which result in the measured relative rotation angle position of the camshaft executing a sawtooth oscillation about the actual rotation angle position. This has a negative effect on the control precision and also results in an increased power consumption by the EC motor.